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i No Drawing: Application filed 'Deoember 3,.

patented July 18, 1933 UNITED A v 1,18,648 PATENT oFFlcE ERNST KOBTEN, F. -THE-MAIN-FIElCI-IENHEIM, GERMANY, ASSI GNOR 'I'O I. G. FARBENINDUSTRIE AKTIE-NGESELLSCHAFT, OF FBANKFORT-ON-THE-MAIN,

GERMANY, A coRPoRA'rIoNoF GERMANY PROCESS non MANUFACTURING AR-TETRAHYDRONAPHTHOL nrHnRs wherein the Xs mean hydrogen or mono 9 valent substituents and n means the number 1 or 2;, with hydrogen in the presence of a base metal hydrogenation catalyst, in a smooth reaction practically without the formation of by-"products, ar-tetrahydronaphthol ethers are obtained corresponding to the generaliformula:

C 3H X n (O-alkyl) wherein the Xs and n have the aforesaid signification and the ether groups are attached to the aromatic not hydrogenated nucleus. The result of this process of mine is a quite unexpected one, since usually, when hydrogenating naphthols, the nucleus containing the hydroxy-group is hydrogenated and; On "the other hand, when hydrogenating in the presence of a noble metal hydrogenation catalyst, generally entirely hydrogenated products are obtained. My process of hydrogenation is advantageouslycarried out in the presence of an organic diluent.

Nearl all the ar-tetrahydronaphthol others '0 tainable by present process are unknown hitherto. They may be employed as perfume ingredients because of their agreeable fruit-like scent and also as starting materials forthe manufacture of dyestuffs and pharmaceutical products.

In order to further illustrate my invention the following examples are given the parts being weight and all temperatures incentigrade degrees. But I Wish it to be understood that I am notlimited to the-particular conditions nor to the specific products mentioned therein, i

formula IOCH;

-100 parser tetrahydronaphthalene and 7 1928, Scria1'No. 323,586, and in Germany December. 6, 1927.

hydronaphthalene passes over below 100.

Then the new ar-1-methoxytetrahydronaphthalene of the formula:

distils constantly at 113. It is a clear easily mobileoil of an agreeable aromatic smell.

Example 2 200 parts of a-naphthol-ethyl-ether of the formula:

are heated with 4 parts of a reduced nickel catalyst and hydrogen under a pressure of 50 atmospheres in an autoclave provided with a stirrer. At about a strong absorptionof hydrogen begins. lVhen an amount corresponding to 2 molecules of hydrogen is taken up, the reaction product is separated from the catalyst. It represents ar l-ethoxyu tetrahydronaphthalene of the formula:

H; (i) C211 being'a clear oil boiling at 122 under a pressure of '9 mm as described in literature (Berichte der deutschen chemischen Gesellschaft, vol. 23, page 21 7) i Example 3 500 parts of ,B-naphthol-methyl-ether of the formula:

OOH:

distils constantly at 118" under a pressure of 9 mm, as described in literature (Liebigs Annalen, VOl. 426, page 121).

Example 4 When in Example 3 B-naphthol-methylether is replaced by the corresponding ethylether of the formula:

the new ar-Q-ethoxy-tetrahydronaphthalene is obtained. It corresponds to the formula and represents an easily mobile oil of an agreeable fruit-like smell boiling at 123 under a pressure of8 mm.

Example 5 150 parts of B-naphthol-n-propylether of the formula:

are heated with 2.25 parts of catalyst containing nickel and pumice under a hydrogen pressure of 30 atmospheres while stirring. The absorption occurs Very quickly already at about and is finished when 2 molecules of hydrogen are introduced. The new ar-2- n propyloxy tetrahydro naphthalene thus obtained corresponds to the formula:

It represents a clear agreeably smelling oil boiling at 140 under a pressure of 10 mm.

Example 6 100 parts of ,8-naphthol isopropylether of the formula:

OW fJHa v i and 2 parts of a previously reduced catalyst containing nickel and kieselguhr are hydrogenated according to the foregoing examples. The formed new ar-2-isopropyloXy-tetrahydronaphthalene of the formula:

CH: 1512- O-fJH fJHz H2 being a clear oil of an aromatic smell, boils under a pressure of 9 mm at 135136.

Example 7' fl-naphthol-isobutyl-ether of the formula:

yields when treated in an analogous manner the new ar-Q-isobutyloxy-tetrahydro-naphthalene of the formula:

It boils under a. pressure of 12 mm at 146148 as a clear oil of a less strong aromatic smell.

Example8 parts of 1A-dihydroxy-naphtha1enedimethylether of the formula:

OH: and 1 part of a catalyst containing nickel,

cerium and pumice are. hydrogenated; in .the above mentioned. manner; The-absorption occurs violently at about .8090 and is finished when 2molecules ofhydrogen are taken 5 up. The new ar-l.4 dimethoxy-tetrahydronaphthalene thus obtained; corresponds to the formula:

H1 'O-CH3 50 parts of decahydronaphthalene and ence of a base metal hydrogenation catalyst parts of a catalyst containing nickel and pumice are heated in an autoclave provided 8 with a stirrer under a hydrogen pressure of -60 atmospheres. The absorption occurs very smoothly at 100-150". The formed 11 e W ar-l-acetylamino-2-ethoxy-tetrahydronaphthalene of the formula:

I Hi NH-oo-om n o-cin.

crystallizes from benzine in colorless fibers melting at about 149. It yields when saponified for instance by means of hydrochloric acid in butylic alcohol ar-1-amino-2- ethoxy-tetrahydronaphthalene of the formula:

, H: NH:

H OC2H5 1%, melting at 54-55 when recrystallized from benzine or methyl-alcohol. a

I claim: 1. A process which comprises treating a naphtholether of the general formula:

wherein X means hydrogen or an acylamino 6; group, and n means the number 1 or 2, with hydrogen in the presence of a :base metal hydrogenation catalyst.

2. A process which comprises treating a naphtholether of the general formula :7

wherein X means hydrogen or an acylamino group, and n means the number 1 or 2, with hydrogen under superatmospheric pressures in the presenceof a base netal hydrogenation catalyst with the addition of an organic diluent.

3. A process which comprises treating a naphtholether of the general formula:

f whereinX means hydrogen or an acyla'mino group, andn the number 1 or 2, with hydrogen under pressures between about 20 and about 55 atmospheres and temperatures between about and about 150 in the preswith the addition of an organic diluent.

4:. A process which comprises treating a B- naphtholether of the general formula:

wherein R and R mean hydrogen or alkylgroups, with hydrogen in the presence of a base metal hydrogenation catalyst.

'5. A process which comprises treating a ,8- naphtholether of the general formula:

wherein R and R means hydrogen or alkylgroups, with hydrogen under superatmospheric pressures in the presence of a base metal hydrogenation catalyst with the addition of an organic diluent.

6. A process which comprises treating a beta-naphtholether of the general formula:

R1 O( l--Rg alkyl wherein R and R mean hydrogen or alkyl groups, with hydrogen under pressures between about 20 and about atmospheres and temperatures between about 50 and about 150 in the presence of a base metal hydrogenation catalyst with the addition of an or ganic diluent.

7. As a new compound the ar-2-ethoxy-,

tetrahydronaphthalene of the probable formula:

representing an easily mobile oil boiling at 123 under a pressure of 8 mm.

8. As new compounds the ar-Q-alkoxytetrahydronaphthalenes corresponding to the general formula:

wherein R and R mean hydrogen or alkyl groups, which compounds are colorless substances ofa relatively low melting point, soluble in organic solvents, insoluble in water.

. oxy-tetrahydronaphthalene of the formula:

9. As anew compound, the ar-fZ-isopropyh oxytetrahydronaphthalene of the formula being a clear oil of an aromatic odor and boiling under a pressure of 12 mm at 146 to 148 C.

ERNSTv KORTEN.

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